It's not "termination on any action against Facebook", the termination is only for:

1. filing a patent infringement against Facebook (for anything, related or unrelated to React)

2. filing a patent infringement counterclaim against Facebook for patents related to React (after Facebook have first filed a patent infringement claim against you for patents on anything)

3. filing a patent infringement against anyone for patents related to React

[edit]

> if Facebook infringes on patents you own you can't take action against them if you are using React.

You can take action against them, you just don't have a patent grant once you do.